1. Field of the Invention
This invention relates to flexible couplings for transmitting torsion from a drive shaft to a driven shaft while accommodating misalignment of the shafts with respect to each other and more particularly, to a flexible coupling having quick-disconnect coupling hubs designed to facilitate quick and easy replacement of the flexible connector element of the coupling when the flexible connector wears out or becomes damaged. In a first preferred embodiment of the invention the drive shaft and adjacently-aligned driven shaft each slidably receive a cylindrical hub adjustably mounted on the respective shaft by means of a key removably seated in a slot shaped in the shaft and an adjacently-aligned slot shaped in the hub. An annular coupling flange is then removably mounted on each hub by means of ALLEN screws threaded radially through the flange to reversibly engage a groove shaped circumferentially in the surface of the hub. Each coupling flange receives the corresponding end of a corrugated, elastomeric flexible connector which spans the coupling flanges to transmit torsion from the drive shaft to the driven shaft as the drive shaft is rotated. Inadvertent or operational misalignment or vibration of the shafts with respect to each other is accommodated by distortion of the resilient flexible connector. In a second preferred embodiment of the invention each coupling flange is removably seated on the corresponding hub by means of a split ring, removably mounted in an annular groove shaped circumferentially in the surface of the hub, for reversibly engaging the coupling flanges. In a third preferred embodiment each coupling flange is removably mounted on the corresponding hub by means of a key removably seated in a slot shaped in the hub and adjacently-aligned slot shaped in the coupling flange.
One of the problems encountered in using conventional flexible coupling devices is the requirement of complete or substantially complete disassembly of the coupling elements from the respective shafts in order to replace the flexible connector when the connector becomes damaged or worn. The flexible coupling with quick-disconnect coupling hubs of this invention represents a considerable improvement over such conventional flexible coupling devices due to the ease with which the flexible connector may be replaced. The hub and/or coupling flange elements of the flexible coupling can be slidably displaced on the respective shafts and the flexible connector disengaged from the coupling flanges and removed from the flexible coupling, by simply loosening the hub ALLEN screws or removing the snap ring which secures the coupling flange on the hub, such that disassembly and removal of the hub and coupling flange elements from the shaft is unnecessary.
2 . Description of the Prior Art
Various devices for transmitting torsion from one shaft to another while compensating for misalignment between the shafts, are known in the art. U.S. Pat. No. 2,867,102, dated Jan. 6, 1959, to William A. Williams, describes "Flexible Coupling for Shafts" in which a flexible connecting member is mounted between socket members provided on opposing ends of respective shafts. The tubular connecting member is split longitudinally to facilitate removable connection with the socket members. The surfaces of the connecting member engage each other at the splits to interlock in such a way as to avoid distortion of the connecting member when under torsional strain. U.S. Pat. No. 2,867,103, dated Jan. 6, 1959, also to W. A. Williams, details "Gripping Arrangements For Flexible Couplings For Power Transmission Shafts" characterized by a flexible connector having end portions which cooperate with corresponding coupling hubs in a jamming action which tightens the connection between the connector and hubs. Since the end portions of the flexible connector do not extend beyond the respective hubs, the ends of the connector do not wrap around the hubs and pull the connector ends out of engagement with the hubs when the connector is subjected to torsional stress and deformation under working load. U.S. Design Pat. No. 240,327, dated Jun. 22, 1976, to Lewis E. Baer, illustrates a "Flexible Shaft Coupling". U.S. Pat. No. 4,304,501, dated Dec. 8, 1981, to William J. Gordon, et al, discloses a "Disconnect Gear Coupling" characterized by an internally-toothed sleeve which reversibly engages external teeth formed on a pair of hubs adapted to be mounted on driving and driven shafts. A travel screw is threadably seated in a bore provided in a flange mounted on the sleeve and extends axially with its outer end journaled and held against rotation in a bore provided in a support bracket which extends radially from the end of one of the hubs. Rotation of the travel screw shifts the sleeve axially to disengage the teeth of the opposite hub. U.S. Pat. No. 4,615,639, dated Oct. 7, 1986, to Ali Seireg, describes a "Key And Key Joint" including a key having a generally solid central portion and a pair of end portions, each including a pair of spaced longitudinal prongs. The key is assembled in the key joint with the slots defined by the longitudinal prongs extending from top to bottom through the key in a radial direction. A key joint thus assembled reduces the stress concentration factor attributable to a key joint assembled with a standard key to provide for a gradual transition between the strain of a shaft and the strain of a hub in torsion.
It is an object of this invention to provide a flexible coupling for connecting a drive shaft with an adjacently-aligned driven shaft and transmitting torsion from the drive shaft to the driven shaft responsive to rotation of the drive shaft.
Another object of this invention is to provide a flexible coupling in which misalignment or vibration of the drive shaft with respect to the driven shaft is accommodated by the resiliency of an elastomeric flexible connector.
Still another object of this invention is to provide a flexible coupling characterized by a pair of cylindrical hubs which are removably and adjustably mounted on respective drive and driven shafts and including an annular coupling flange reversibly and fixedly seated on each hub for receiving and engaging the corresponding end of an elastomeric flexible connector which spans the coupling flanges and transmits torsion from the drive shaft to the driven shaft responsive to rotation of the drive shaft.
Yet another object of this invention is to provide a flexible coupling including a flexible connector member which is axially mounted between a first coupling flange reversibly and fixedly seated on a hub mounted on a drive shaft and a second coupling flange similarly secured on a hub mounted on an adjacently-aligned driven shaft, which flexible connector may be quickly and easily removed from the coupling flanges for replacement by disengaging at least one coupling flange from the corresponding hub and sliding the coupling flange on the hub, or by disengaging at least one hub from the corresponding shaft and sliding the hub on the shaft.